请注意,元数据不会被提取,因为mp.getMetadata(MediaPlayer.MetaDATA_ALL,MediaPlayer.BYPASS_MetaDATA_FILTER)不可访问,但您可以尝试使用MediaMetadataRetriever

VideoView

import java.io.IOException;
import java.util.Map;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.res.Resources;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.net.Uri;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.MediaController;
import android.widget.MediaController.MediaPlayerControl;


/**
 * Displays a video file. The VideoView class can load images from varIoUs sources (such as resources or content
 * providers),takes care of computing its measurement from the video so that it can be used in any layout manager,and
 * provides varIoUs display options such as scaling and tinting.
 */
public class VideoView extends SurfaceView implements MediaPlayerControl {

    private String TAG = "VideoView";

    // settable by the client
    private Uri mUri;

    private Map<String,String> mHeaders;

    private int mDuration;

    // all possible internal states
    private static final int STATE_ERROR = - 1;

    private static final int STATE_IDLE = 0;

    private static final int STATE_PREPARING = 1;

    private static final int STATE_PREPARED = 2;

    private static final int STATE_PLAYING = 3;

    private static final int STATE_PAUSED = 4;

    private static final int STATE_PLAYBACK_COMPLETED = 5;

    // mCurrentState is a VideoView object's current state.
    // mTargetState is the state that a method caller intends to reach.
    // For instance,regardless the VideoView object's current state,// calling pause() intends to bring the object to a target state
    // of STATE_PAUSED.
    private int mCurrentState = STATE_IDLE;

    private int mTargetState = STATE_IDLE;

    // All the stuff we need for playing and showing a video
    private SurfaceHolder mSurfaceHolder = null;

    private MediaPlayer mMediaPlayer = null;

    private int mVideoWidth;

    private int mVideoHeight;

    private int mSurfaceWidth;

    private int mSurfaceHeight;

    private MediaController mMediaController;

    private OnCompletionListener mOnCompletionListener;

    private MediaPlayer.OnPreparedListener mOnPreparedListener;

    private int mCurrentBufferPercentage;

    private OnErrorListener mOnErrorListener;

    private int mSeekWhenPrepared; // recording the seek position while preparing

    private boolean mCanPause;

    private boolean mCanSeekBack;

    private boolean mCanSeekForward;

    public VideoView(Context context) {
        super(context);
        initVideoView();
    }

    public VideoView(Context context,AttributeSet attrs) {
        this(context,attrs,0);
        initVideoView();
    }

    public VideoView(Context context,AttributeSet attrs,int defStyle) {
        super(context,defStyle);
        initVideoView();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {
        // Log.i("@@@@","onMeasure");
        int width = getDefaultSize(mVideoWidth,widthMeasureSpec);
        int height = getDefaultSize(mVideoHeight,heightMeasureSpec);
        if(mVideoWidth > 0 && mVideoHeight > 0) {
            if(mVideoWidth * height > width * mVideoHeight) {
                // Log.i("@@@","image too tall,correcting");
                height = width * mVideoHeight / mVideoWidth;
            } else if(mVideoWidth * height < width * mVideoHeight) {
                // Log.i("@@@","image too wide,correcting");
                width = height * mVideoWidth / mVideoHeight;
            } else {
                // Log.i("@@@","aspect ratio is correct: " +
                // width+"/"+height+"="+
                // mVideoWidth+"/"+mVideoHeight);
            }
        }
        // Log.i("@@@@@@@@@@","setting size: " + width + 'x' + height);
        setMeasuredDimension(width,height);
    }

    @Override
    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
        super.onInitializeAccessibilityEvent(event);
        event.setClassName(VideoView.class.getName());
    }

    @Override
    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfo(info);
        info.setClassName(VideoView.class.getName());
    }

    public int resolveAdjustedSize(int desiredSize,int measureSpec) {
        int result = desiredSize;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        switch(specMode) {
            case MeasureSpec.UNSPECIFIED:
                /*
                 * Parent says we can be as big as we want. Just don't be larger than max size imposed on ourselves.
                 */
                result = desiredSize;
                break;

            case MeasureSpec.AT_MOST:
                /*
                 * Parent says we can be as big as we want,up to specSize. Don't be larger than specSize,and don't be
                 * larger than the max size imposed on ourselves.
                 */
                result = Math.min(desiredSize,specSize);
                break;

            case MeasureSpec.EXACTLY:
                // No choice. Do what we are told.
                result = specSize;
                break;
        }
        return result;
    }

    private void initVideoView() {
        mVideoWidth = 0;
        mVideoHeight = 0;
        getHolder().addCallback(mSHCallback);
        getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        setFocusable(true);
        setFocusableInTouchMode(true);
        requestFocus();
        mCurrentState = STATE_IDLE;
        mTargetState = STATE_IDLE;
    }

    public void setVideoPath(String path) {
        setVideoURI(Uri.parse(path));
    }

    public void setVideoURI(Uri uri) {
        setVideoURI(uri,null);
    }

    /**
     * @hide
     */
    public void setVideoURI(Uri uri,Map<String,String> headers) {
        mUri = uri;
        mHeaders = headers;
        mSeekWhenPrepared = 0;
        openVideo();
        requestLayout();
        invalidate();
    }

    public void stopPlayback() {
        if(mMediaPlayer != null) {
            mMediaPlayer.stop();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            mTargetState = STATE_IDLE;
        }
    }

    private void openVideo() {
        if(mUri == null || mSurfaceHolder == null) {
            // not ready for playback just yet,will try again later
            return;
        }
        // Tell the music playback service to pause
        // TODO: these constants need to be published somewhere in the framework.
        Intent i = new Intent("com.android.music.musicservicecommand");
        i.putExtra("command","pause");
        getContext().sendBroadcast(i);

        // we shouldn't clear the target state,because somebody might have
        // called start() prevIoUsly
        release(false);
        try {
            mMediaPlayer = new MediaPlayer();
            mMediaPlayer.setOnPreparedListener(mPreparedListener);
            mMediaPlayer.setOnVideoSizeChangedListener(mSizeChangedListener);
            mDuration = - 1;
            mMediaPlayer.setOnCompletionListener(mCompletionListener);
            mMediaPlayer.setOnErrorListener(mErrorListener);
            mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener);
            mCurrentBufferPercentage = 0;
            mMediaPlayer.setDataSource(getContext(),mUri,mHeaders);
            mMediaPlayer.setDisplay(mSurfaceHolder);
            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mMediaPlayer.setScreenOnWhilePlaying(true);
            mMediaPlayer.prepareAsync();
            // we don't set the target state here either,but preserve the
            // target state that was there before.
            mCurrentState = STATE_PREPARING;
            attachMediaController();
        } catch(IOException ex) {
            Log.w(TAG,"Unable to open content: " + mUri,ex);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            mErrorListener.onError(mMediaPlayer,MediaPlayer.MEDIA_ERROR_UNKNOWN,0);
            return;
        } catch(IllegalArgumentException ex) {
            Log.w(TAG,0);
            return;
        }
    }

    public void setMediaController(MediaController controller) {
        if(mMediaController != null) {
            mMediaController.hide();
        }
        mMediaController = controller;
        attachMediaController();
    }

    private void attachMediaController() {
        if(mMediaPlayer != null && mMediaController != null) {
            mMediaController.setMediaPlayer(this);
            View anchorView = this.getParent() instanceof View ? (View)this.getParent() : this;
            mMediaController.setAnchorView(anchorView);
            mMediaController.setEnabled(isInPlaybackState());
        }
    }

    MediaPlayer.OnVideoSizeChangedListener mSizeChangedListener = new MediaPlayer.OnVideoSizeChangedListener() {

        public void onVideoSizeChanged(MediaPlayer mp,int width,int height) {
            mVideoWidth = mp.getVideoWidth();
            mVideoHeight = mp.getVideoHeight();
            if(mVideoWidth != 0 && mVideoHeight != 0) {
                getHolder().setFixedSize(mVideoWidth,mVideoHeight);
            }
        }
    };

    MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener() {

        public void onPrepared(MediaPlayer mp) {
            mCurrentState = STATE_PREPARED;

            // Get the capabilities of the player for this stream

            // -_- where is the method ?
            // Metadata data = mp.getMetadata(MediaPlayer.MetaDATA_ALL,MediaPlayer.BYPASS_MetaDATA_FILTER);

            // use MediaMetadataRetriever to retrieve Metadata
            Metadata data = null;

            if(data != null) {
                mCanPause = ! data.has(Metadata.PAUSE_AVAILABLE) || data.getBoolean(Metadata.PAUSE_AVAILABLE);
                mCanSeekBack = ! data.has(Metadata.SEEK_BACKWARD_AVAILABLE) || data.getBoolean(Metadata.SEEK_BACKWARD_AVAILABLE);
                mCanSeekForward = ! data.has(Metadata.SEEK_FORWARD_AVAILABLE) || data.getBoolean(Metadata.SEEK_FORWARD_AVAILABLE);
            } else {
                mCanPause = mCanSeekBack = mCanSeekForward = true;
            }

            if(mOnPreparedListener != null) {
                mOnPreparedListener.onPrepared(mMediaPlayer);
            }
            if(mMediaController != null) {
                mMediaController.setEnabled(true);
            }
            mVideoWidth = mp.getVideoWidth();
            mVideoHeight = mp.getVideoHeight();

            int seekToPosition = mSeekWhenPrepared; // mSeekWhenPrepared may be changed after seekTo() call
            if(seekToPosition != 0) {
                seekTo(seekToPosition);
            }
            if(mVideoWidth != 0 && mVideoHeight != 0) {
                // Log.i("@@@@","video size: " + mVideoWidth +"/"+ mVideoHeight);
                getHolder().setFixedSize(mVideoWidth,mVideoHeight);
                if(mSurfaceWidth == mVideoWidth && mSurfaceHeight == mVideoHeight) {
                    // We didn't actually change the size (it was already at the size
                    // we need),so we won't get a "surface changed" callback,so
                    // start the video here instead of in the callback.
                    if(mTargetState == STATE_PLAYING) {
                        start();
                        if(mMediaController != null) {
                            mMediaController.show();
                        }
                    } else if( ! isPlaying() && (seekToPosition != 0 || getCurrentPosition() > 0)) {
                        if(mMediaController != null) {
                            // Show the media controls when we're paused into a video and make 'em stick.
                            mMediaController.show(0);
                        }
                    }
                }
            } else {
                // We don't know the video size yet,but should start anyway.
                // The video size might be reported to us later.
                if(mTargetState == STATE_PLAYING) {
                    start();
                }
            }
        }
    };

    private MediaPlayer.OnCompletionListener mCompletionListener = new MediaPlayer.OnCompletionListener() {

        public void onCompletion(MediaPlayer mp) {
            mCurrentState = STATE_PLAYBACK_COMPLETED;
            mTargetState = STATE_PLAYBACK_COMPLETED;
            if(mMediaController != null) {
                mMediaController.hide();
            }
            if(mOnCompletionListener != null) {
                mOnCompletionListener.onCompletion(mMediaPlayer);
            }
        }
    };

    private MediaPlayer.OnErrorListener mErrorListener = new MediaPlayer.OnErrorListener() {

        public boolean onError(MediaPlayer mp,int framework_err,int impl_err) {
            Log.d(TAG,"Error: " + framework_err + "," + impl_err);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            if(mMediaController != null) {
                mMediaController.hide();
            }

            /* If an error handler has been supplied,use it and finish. */
            if(mOnErrorListener != null) {
                if(mOnErrorListener.onError(mMediaPlayer,framework_err,impl_err)) {
                    return true;
                }
            }

            /*
             * Otherwise,pop up an error dialog so the user knows that something bad has happened. Only try and pop up
             * the dialog if we're attached to a window. When we're going away and no longer have a window,don't bother
             * showing the user an error.
             */
            if(getWindowToken() != null) {
                Resources r = getContext().getResources();
                int messageId;

                if(framework_err == MediaPlayer.MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK) {
                    messageId = R.string.VideoView_error_text_invalid_progressive_playback;
                } else {
                    messageId = R.string.VideoView_error_text_unknown;
                }

                new AlertDialog.Builder(getContext()).setMessage(messageId).setPositiveButton(R.string.VideoView_error_button,new DialogInterface.OnClickListener() {

                    public void onClick(DialogInterface dialog,int whichButton) {
                        /*
                         * If we get here,there is no onError listener,so at least inform them that the video is over.
                         */
                        if(mOnCompletionListener != null) {
                            mOnCompletionListener.onCompletion(mMediaPlayer);
                        }
                    }
                }).setCancelable(false).show();
            }
            return true;
        }
    };

    private MediaPlayer.OnBufferingUpdateListener mBufferingUpdateListener = new MediaPlayer.OnBufferingUpdateListener() {

        public void onBufferingUpdate(MediaPlayer mp,int percent) {
            mCurrentBufferPercentage = percent;
        }
    };

    /**
     * Register a callback to be invoked when the media file is loaded and ready to go.
     * 
     * @param l The callback that will be run
     */
    public void setOnPreparedListener(MediaPlayer.OnPreparedListener l) {
        mOnPreparedListener = l;
    }

    /**
     * Register a callback to be invoked when the end of a media file has been reached during playback.
     * 
     * @param l The callback that will be run
     */
    public void setOnCompletionListener(OnCompletionListener l) {
        mOnCompletionListener = l;
    }

    /**
     * Register a callback to be invoked when an error occurs during playback or setup. If no listener is specified,or
     * if the listener returned false,VideoView will inform the user of any errors.
     * 
     * @param l The callback that will be run
     */
    public void setOnErrorListener(OnErrorListener l) {
        mOnErrorListener = l;
    }

    SurfaceHolder.Callback mSHCallback = new SurfaceHolder.Callback() {

        public void surfaceChanged(SurfaceHolder holder,int format,int w,int h) {
            mSurfaceWidth = w;
            mSurfaceHeight = h;
            boolean isValidState = (mTargetState == STATE_PLAYING);
            boolean hasValidSize = (mVideoWidth == w && mVideoHeight == h);
            if(mMediaPlayer != null && isValidState && hasValidSize) {
                if(mSeekWhenPrepared != 0) {
                    seekTo(mSeekWhenPrepared);
                }
                start();
            }
        }

        public void surfaceCreated(SurfaceHolder holder) {
            mSurfaceHolder = holder;
            openVideo();
        }

        public void surfaceDestroyed(SurfaceHolder holder) {
            // after we return from this we can't use the surface any more
            mSurfaceHolder = null;
            if(mMediaController != null)
                mMediaController.hide();
            release(true);
        }
    };

    /*
     * release the media player in any state
     */
    private void release(boolean cleartargetstate) {
        if(mMediaPlayer != null) {
            mMediaPlayer.reset();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            if(cleartargetstate) {
                mTargetState = STATE_IDLE;
            }
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if(isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onTrackballEvent(MotionEvent ev) {
        if(isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onKeyDown(int keyCode,KeyEvent event) {
        boolean isKeyCodeSupported = keyCode != KeyEvent.KEYCODE_BACK && keyCode != KeyEvent.KEYCODE_VOLUME_UP
                && keyCode != KeyEvent.KEYCODE_VOLUME_DOWN && keyCode != KeyEvent.KEYCODE_VOLUME_MUTE && keyCode != KeyEvent.KEYCODE_MENU
                && keyCode != KeyEvent.KEYCODE_CALL && keyCode != KeyEvent.KEYCODE_ENDCALL;
        if(isInPlaybackState() && isKeyCodeSupported && mMediaController != null) {
            if(keyCode == KeyEvent.KEYCODE_HEADSETHOOK || keyCode == KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE) {
                if(mMediaPlayer.isPlaying()) {
                    pause();
                    mMediaController.show();
                } else {
                    start();
                    mMediaController.hide();
                }
                return true;
            } else if(keyCode == KeyEvent.KEYCODE_MEDIA_PLAY) {
                if( ! mMediaPlayer.isPlaying()) {
                    start();
                    mMediaController.hide();
                }
                return true;
            } else if(keyCode == KeyEvent.KEYCODE_MEDIA_STOP || keyCode == KeyEvent.KEYCODE_MEDIA_PAUSE) {
                if(mMediaPlayer.isPlaying()) {
                    pause();
                    mMediaController.show();
                }
                return true;
            } else {
                toggleMediaControlsVisiblity();
            }
        }

        return super.onKeyDown(keyCode,event);
    }

    private void toggleMediaControlsVisiblity() {
        if(mMediaController.isShowing()) {
            mMediaController.hide();
        } else {
            mMediaController.show();
        }
    }

    public void start() {
        if(isInPlaybackState()) {
            mMediaPlayer.start();
            mCurrentState = STATE_PLAYING;
        }
        mTargetState = STATE_PLAYING;
    }

    public void pause() {
        if(isInPlaybackState()) {
            if(mMediaPlayer.isPlaying()) {
                mMediaPlayer.pause();
                mCurrentState = STATE_PAUSED;
            }
        }
        mTargetState = STATE_PAUSED;
    }

    public void suspend() {
        release(false);
    }

    public void resume() {
        openVideo();
    }

    // cache duration as mDuration for faster access
    public int getDuration() {
        if(isInPlaybackState()) {
            if(mDuration > 0) {
                return mDuration;
            }
            mDuration = mMediaPlayer.getDuration();
            return mDuration;
        }
        mDuration = - 1;
        return mDuration;
    }

    public int getCurrentPosition() {
        if(isInPlaybackState()) {
            return mMediaPlayer.getCurrentPosition();
        }
        return 0;
    }

    public void seekTo(int msec) {
        if(isInPlaybackState()) {
            mMediaPlayer.seekTo(msec);
            mSeekWhenPrepared = 0;
        } else {
            mSeekWhenPrepared = msec;
        }
    }

    public boolean isPlaying() {
        return isInPlaybackState() && mMediaPlayer.isPlaying();
    }

    public int getBufferPercentage() {
        if(mMediaPlayer != null) {
            return mCurrentBufferPercentage;
        }
        return 0;
    }

    private boolean isInPlaybackState() {
        return (mMediaPlayer != null && mCurrentState != STATE_ERROR && mCurrentState != STATE_IDLE && mCurrentState != STATE_PREPARING);
    }

    public boolean canPause() {
        return mCanPause;
    }

    public boolean canSeekBackward() {
        return mCanSeekBack;
    }

    public boolean canSeekForward() {
        return mCanSeekForward;
    }
}